The Giants claimed former Chargers LB Nigel Harris off waivers on Tuesday and placed DE Romeo Okwara on the injured reserve.
Okwara landed on the IR after he sprained his knee last week, while Harris was waived by the Chargers on Monday.
Harris recorded a pair of tackles on kickoffs late in the Chargers' win over the Giants at MetLife Stadium on Oct. 8. He joined the Chargers in May as a rookie free agent after he went undrafted out of the University of South Florida.
Harris saw playing time in each of the Chargers' first five games this season, but was inactive on Sunday when the Chargers faced the Raiders. He has tallied eight tackles on defense and three stops on special teams this season.
Okwara played in the Giants' first five games before he was ruled inactive for Week 6.